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Dont go over 9:1, that should give you some kick when your turbo is not fully spooled. then when it kicks in
wewt!!

A supercharger and a turbocharger do the same thing, but use different methods to do it. Both are a class of parts known as 'forced induction', as opposed to natural aspiration. Turbo- and super-chargers forcefully suck air in and blow it into the combustion chambers, rather than rely on the intake stroke of the piston to suck air in from the plenum.

The supercharger is the older piece of equipment. Superchargers are usually run by a belt, or less commonly, a gear, and use a turbine called a 'compressor' to suck air in, compress it, and force-feed it into the cylinder. however, superchargers are parasitic in nature, using the crank pulley to operate. This lowers the amount of power they will produce, as some of the extra power is spent on rotating the supercharger.

A turbocharger is similar, but uses the exhaust gasses moving over a turbine to spin the compressor. Turbochargers are not parasitic in nature, allowing them to generate more horsepower than a supercharger of equivalent C.F.M. rating due to the turbine being spun by the exhaust flow.

The biggest difference is in the speed of reaction. A turbo suffers what is called 'turbo lag' when the exhaust airflow is not fast enough to spin the compressor at a desireable level. A supercharger, on the other hand, has instant response due to the compressor being driven by the crank pulley. Superchargers, therefore, are better for low-RPM boosting, and superchargers being better for high-RPM boosting.

Both of these systems are very similar in their operation, typically requiring dedicated oil plumbing, lower engine compressions to avoid predetonation, and usually the integration into the intake of a blow-off valve and an intercooler.

To decide whether you want to supercharge or turbocharge, you must ask yourself a few questions first.

- What type of engine are you running? V-engines are easier to adapt to superchargers than inline-engines, which have the intake on the side, rather than the top.

- how much weight are you willing to carry? Superchargers typically weigh more than turbochargers due to their mounting hardware and more robust construction

- what is the application? If you're drag racing, a supercharger is for you. If you're drifting, you'll probably want a turbocharger.

In reality, neither the supercharger or the turbocharger is better. Both are tools to get the same job done in different applications. Before considering either though, and converting an N/A to forced induction, read up on both extensively. And try to pick up the book 'Maximum Boost'. It's basically the forced induction bible.

^ I think most of us knew the basics of turbo and supercharging. No need to necropost a sticked thread to basically summarize the entire thread. Your whole post looks copy-pasted too...However it's rather informative.

Welcome to the forums btw.

This post has been edited by Hachi_Roku on Nov 23 2008, 12:39 AM

WOW a Supercharger must be WAY better then the turbocharger then! Nah I'm just mess wit ya.
Corrected:

There's no replacement for displacement. NA all the way and all that. The problem with turbos is that you have to rev your engine a lot to get noticeable boost. In a race car, that's no problem, you have the pedal to the metal most of the time. On the street where mileage and speed limits are factors you have to think about, low end power is much more important. The most efficient way to drive is to short shift your way to the highest gear feasible for the speed you want to go. Piston engines operate most efficiently at low RPM's with high throttle opening. On the street, you're rarely revving to redline, so all the noticeable power comes in the form of low end torque. The bigger your engine (generally speaking), the more torque, which allows for longer gearing, which makes it more comfortable on the street.

In short, if you have a high revving engine(read: small) with short gearing, turbocharging is the best solution. If you have a big v8, a supercharger will probably net you the biggest power gains. If you have a formula 1 engine or anything over 7 liters: Told you NA was the best.

This post stinks 10 shades of angry.

Turbo will ALWAYS net the biggest horsepower gains per pound of boost. Good turbos build boost in LOW rpms, and maintain it to redline. Piston engines highest efficiency is dependant on MANY MANY MANY factors, To say they opperate most efficiently at low rpms with high throttle is nothing but a complete and utter farse. Formula 1 engines are not turbo because they are not allowed to be. If they were allowed to be, they would be.

im glad i ran into this thread. I'll be going supercharger.

Heh, not really angry, I just like my NA. Formula 1 used to run turbos, and they had more than a thousand horsepower. It is true that piston engines found in pretty much every car on the road (I might be wrong on some engines, not all are the same, and I'm not entirely sure about turbocharged engines because they don't factor pumping losses the same way NA engines do) but friction plays a higher role at higher RPMs and pumping losses sap power at low throttle.

Also of course turbos will net the most horsepower per pound of boost, they don't take power from any of the drive components.

With what car? If it's a small four-banger you can forget about that.

@Cactus: Look up the new Hyundai Genesis Coupe 2.0T. Full boost at 3XXX RPM. That's not all that bad for a car that was meant for usual track sessions.

This post has been edited by chillined on Apr 13 2009, 08:00 AM

http://jalopnik.com/5072100/hyundai-releas...ger-gets-30-mpg

I'd love to have that car, btw.

Even with the 16G, I'm still getting full boost by 3200. Oh, and not revving to redline on the daily is a lie.

With the newer turbochargers coming out being more efficient, coming on boost faster (Not by a whole lot but its noticable) and producing more power/torque, its increasingly more difficult to justify the use of a supercharger. Its becoming more of a personal choice rather than a logical choice.

@ Catus - So according to your logics, NA is best because you must have 7L or in short, a small capacity race engine? A lil shortsighted lol

I'm an advocate of NA/Mechanical tuning, the sound and response via the pedal is what I enjoy most but I love the simplicity when chasing power and torque, the use of Force Induction. Personally I find NA more refinied, more challenging to gain any power/torque without sacrificing too much of something else and sounds nothing like Force Induced cars =P (Totally subjective here, its not logical) The basic ways of increasing power/torque with NA is with capacity changes or by a combination of camshaft, rev limiter raised to take advantage, compression increase ditto as before. BUT if you get this wrong, you end up with a dead engine or an engine that just isn't right... Like it's lost its magic?

Force Induction isn't that much easier but you've got more room to play with especially with turbocharging, match the right turbo with the right parts and electronical wizardary, you'll can have a nice responsive boost level then push a lovely red button when you're on the straight and have the boost level increase, best of both worlds. Not that simple I know but its just an example =)

This post has been edited by DreadAngel on Apr 16 2009, 04:35 PM

The really shitty thing about NA, is that you're limited almost in all cases. Sure colder air and free-flowing exhaust helps, but COMPRESSION is what you need. When you raise that, you need to raise the octane of your fuel. Also, NA Tuning is quite expensive to match forced induction. A insanely good tune is very necessary, and good fuel. Not only that, but excellent head work and high compression is expensive to maintain.
But hell, I sure do love High revving NA's, there's none like it.

And exactly what do you drive, my friend? What NA are you driving that is so superior to others?

First of all, this entire thread is about supercharged vs. turbocharged, not FI vs. NA. And obviously you haven't driven a recent turbocharged engine, otherwise you'd think twice before making an irresponsible comment generalizing all engines of a given setup based on its stereotype that is a couple decades old.

Granted nothing screams like a high-revving NA motor, but there are so many advantages to FI. There's a reason why BMW's M division is switching to turbocharging. While its increased fuel economy is both an advantage and a huge driving force (given the upcoming CAFE standards), the fact that the current M V-10 puts out 507 hp and 383 lb.-ft while their upcoming twin-turbo V-8 puts out 550 hp and 501 lb.-ft (over a much broader rev range while hitting earlier as well) while also getting better fuel consumption, it's a not a difficult decision. Plus there is a lot of technology out there to combat turbo lag, like twin-scroll layouts or variable turbine geometry.

Totally agree with you there!

NA tuning, you can't justify the cost to match the output of Forced Induction. The lengths to get remotely close is impossible! Not all of us can afford the 15K build then to strip down the block every 10,000km to have it checked and put back together again...

NA tuning is imo about how badly you want it ($$$ + Dedication) and how much you want to sacrifice (trade offs)...

Boosted engines already require higher octane fuel, so it more levels the playing field as opposed to disadvantaging you. And I highly doubt that a high compression engine is more expensive to maintain than a boosted engine, they both see higher cylinder pressure at ignition. All in all, it's probably a wash.

Also, keep in mind that driveability is also affected more so in the case of an NA. Like in the above example where you raise the compression ratio and the redline, sure, the engine can produce more power up top but down low, it's miserable. Just look at a stock S2000. Great power up top (240 hp!) and amazing engineering and hp/liter (110-120 hp, depending on year), but if the engine is spinning at anything less than 6k rpm, you really don't have much punch to do anything. This happens with a lot of other small-displacement NA engines that get tuned for significant gains over stock numbers, lots of zip comes at the cost of sacrificed low-end and mid-range along with your ears bleeding from the noise when it's finally making power.

Turbos, on the other hand, already add a lot of power and a pretty solid mid-range, particularly when it's a stock unit or at least an aftermarket one tuned properly. All I really need is 2500 rpm to really start flying by cars if I need to (or 3000 if I'm in top gear). At rpms like that or lower, the NA cars might have a slightly quicker initial throttle response, but turbos can kick in relatively quickly these days. Even a lot of guys with aftermarket turbos have them at full boost relatively early, so they're really punchy and very streetable. And probably much cheaper when trying to reach a certain hp target.

Obviously if you slap on a huge turbo if you have goals of 800 hp on a tiny motor, then you are going to have some serious driveability issues, but those are usually track-dedicated cars.

"A full 460 lb.-ft. is available from as low as 1,950 rpm up to 5,000 rpm. Every throttle input is met with exceptional response and phenomenal acceleration."
"Matching the superlative performance of the car is the efficiency with which it is generated. In spite of the increase in power and torque, the 911 Turbo offers a further reduction in fuel consumption." - World Auto News & Reviews

the variable turbine turbo from porsche

This post has been edited by NismoTime on Apr 17 2009, 12:13 PM

^ And once they can mass produce those for the aftermarket at a reasonable price, a lot of four-cylinders will be completely deadly with these.

Well, I just drove my friend's turbocharged and intercooled Civic. It was an experience for an all NA all the time guy (me, if you hadn't read my earlier posts). My engine's more than twice the displacement of his, but his really pulls once the boost kicks in. I guess I shouldn't have been bashing boost. It's a tradeoff. I just find that that loads of torque from idle is nicer on the street than a dump of torque at 3-4000 revs. The lag gets to me. I know you can set it up to minimize lag, but at the cost of top end power. Again, it's a tradeoff.

On topic with the thread, I'm more a fan of superchargers. They spool up proportionately with the engine, which is nice, and they can offer you as much power as you want. Plumbing them is a lot easier than turbos, which require a surfeit of pipes. I think they're much better on the street. On the strip, reducing lag is very appreciable. On the track, you shouldn't have to wait for the turbo to spool more than once, so it's a-ok there. Variable vane turbos are slick.

Or if the regs say you have to.

Much nicer post. Anyway...

Lag generally isn't too much of an issue these days, if you drive properly, i.e. staying in the right gear, which isn't too hard, given the powerband of a properly tuned turbocharged engine, whether factory or not. (Massive turbos will obviously have more noticeable lag.) Like any high-revving NA motor (especially ones with smaller displacements), there's generally a sweet spot in the rev range to keep the rpms at, and the same applies to turbocharged cars, except the sweet spot usually spans a greater range and begins earlier. So maybe you won't be able to stay in top gear at 45 mph and expect a surge of power if you jab at the throttle if you want to accelerate like you would in a larger displacement NA car, but all it takes is a downshift and you're moving. And when you're talking about high-revving, small-displacement NA engines, it might even need a downshift two gears lower.

The compromise these days is far more reasonable than ever before. The lag that you experienced in your friend's Civic is more than likely to be expected. For one thing, it's obviously an aftermarket setup (as no Civics come blown stock), and typically factory setups have more than reasonable setups that are a good compromise with minimal lag being a goal. I'm not sure what model year it was, but assuming it wasn't the current model, then it was probably less than 2.0-liters. Those engines from the factory are already peaky enough as is, with peak torque hitting higher and topping out relatively low (anywhere from 100-140 lb.-ft, depending on which Civic), so adding a turbo won't help its low-end grunt that much, though its mid-range and top-end will be significantly stronger. That's why the larger turbocharged four-cylinders like the Dodge SRT-4, Mazdaspeed 3, Subaru Impreza WRX and STI models have very little lag, given their larger-than-normal displacement for a turbocharged four-cylinder. However, the recent Mini Cooper S has switched from a supercharger to a turbocharger and not only has higher peak hp and torque than before but also a broader powerband, again thanks to improving turbo technology and excellent factory tuning, all despite the engine being only 1.6-liters. And then keep in mind that when cruising in top gear, it's going to drink fuel like a 1.6-liter (or however large the engine is of the vehicle we're talking about) when not in boost, whereas the larger engine will drink like a larger engine, though both have similar power with varied power deliveries.

Superchargers do have some advantages, but their overall gains aren't as significant as turbos, plus they will generally be less fuel efficient in regular, everyday driving while putting more wear-and-tear on your motor, since the supercharger is constantly working and boosting. While I realize that some reputable cars like the Audi S4 and Corvette ZR1 use superchargers, there's a reason why a lot of companies have ditched their superchargers. As I mentioned before, Mini ditched the supercharger for the turbocharged unit, plus Mercedes ditched the supercharged 5.4-liter V-8 in their AMG models for the NA 6.2-liter V-8, though a twin-turbo version of that 6.2-liter has been under development for quite some time. Even their flagship SLR McLaren and its supercharged V-8 got upstaged and put on the backburner by AMG's own twin-turbo V-12 SL65 Black Series, actually costing less money but yielding more power (670 hp) and torque (738 lb.-ft). Even drivers of the previous SVT Cobras would swap out their superchargers for turbos in the hardcore applications. And then let's not forget the plethora of fast cars that have been using turbochargers.

And again, the lag of turbos can sometimes be exaggerated, as there are plenty of ways around them. Stay in the right gear, and you'll be fine. Even when launching, whether on a drag strip or taking off around a track, if you launch properly with boost building, then you'll blast away.

^^^

Ding ding ding!

Combination of turbine sizing and a good tune =) Like any modification, your parts are only as good as their tuner =)

If a car has a potential of 100%...

Parts % + Tuner % + Driver % = % of the potential

hmm i always thought super chargers were good for the boost of power and turbos were for long distance speeds.

Your post does not make any sense. Sorry, but it really doesn't. The boost of power is supposed to be power gains? Yeah, Turbos are more efficient than Superchargers, they provide MORE power using the same boost levels. Long Distance speeds, I don't even know what you're talking about. I can tell you this though, depending on the course or usage of a turbo/supercharger, you can tell which one is more superior to the other.